Phosphate-Solubilizing Pseudomonas sp. Strain P34-L Promotes Wheat Growth by Colonizing the Wheat Rhizosphere and Improving the Wheat Root System and Soil Phosphorus Nutritional Status
- 242 Downloads
Rhizosphere colonization is a requirement for field applications of plant growth-promoting rhizobacteria (PGPR). Complex signal exchanges and mutual recognition occur between microbes and plants. Here, the phosphate-solubilizing strain Pseudomonas sp. P34, which is a type of PGPR with affinity to wheat, was isolated from a wheat rhizosphere via wheat germ agglutinin. A pTR102 plasmid harboring the luciferase luxAB gene was transferred into P34. The labeled strain (P34-L) was then used to track the temporal and spatial characteristics of rhizosphere colonization and examine the effects of colonization on wheat development. The transcript levels of the phosphate transporter gene TaPT4, a phosphorus deficiency indicator, in wheat roots were monitored by quantitative reverse transcription PCR (qRT-PCR). The results indicated that P34-L could survive within the wheat rhizosphere for a long time and colonize new spaces in the wheat rhizosphere following the elongation of wheat roots. Compared with uninoculated wheat plants, plants inoculated with P34-L exhibited significantly increased phosphorus accumulation in the leaves; seedling and root weight; total root length; root projection area; root surface area; and number of root tips, forks, and crossings, thus demonstrating the great value of applying this strain in wheat production by promoting root growth and dry matter accumulation. The downregulation of TaPT4 transcript levels in the wheat roots also suggested that a high-phosphorus environment was established by P34-L. These results lay a foundation for further research on the relationships between PGPR and their host plants. Moreover, a potentially ideal biofertilizer-producing strain for use in sustainable agriculture was developed.
KeywordsPhosphate-solubilizing bacteria Pseudomonas sp. strain P34-L Colonization Growth promotion Root systems Soil phosphorus nutrient status
This work was supported by the National Natural Science Foundation of China (Grant no. 41401269), the Key Projects for Exceptional Young Teachers in Anhui Province (Grant no. 2013SQR015ZD) and funds from Anhui Agricultural University (Grant nos. 2013(5), wd2012-6).
Compliance with Ethical Standards
Conflict of interest
The authors have no conflicts of interest to declare.
- Duan J, Tian H, Drijber RA, Gao Y (2015) Systemic and local regulation of phosphate and nitrogen transporter genes by arbuscular mycorrhizal fungi in roots of winter wheat (Triticum aestivum L.). Plant Physiol Biochem 96:199–208. https://doi.org/10.1016/j.plaphy.2015.08.006 CrossRefPubMedGoogle Scholar
- Guo CJ, Guo L, Li XJ, Gu JT, Zhao M, Duan WW, Ma CY, Lu WJ, Xiao K (2014) TaPT2, a high-affinity phosphate transporter gene in wheat (Triticum aestivum L.), is crucial in plant Pi uptake under phosphorus deprivation. Acta Physiol Plant 36:1373–1384. https://doi.org/10.1007/s11738-014-1516-x CrossRefGoogle Scholar
- Habibi S, Djedidi S, Prongjunthuek K, Mortuza MF, Ohkama-Ohtsu N, Sekimoto H, Yokoyoma T (2014) Physiological and genetic characterization of rice nitrogen fixer PGPR isolated from rhizosphere soils of different crops. Plant Soil 379:51–66. https://doi.org/10.1007/s11104-014-2035-7 CrossRefGoogle Scholar
- Holt JG, Krieg NR, Sneath PHA, Staley JT, Williams ST (1994) Bergey’s manual of systematic bacteriology, 9th edn. Williams and Wilkins, BaltimoreGoogle Scholar
- Mitnura T (1995) Homeostasis and transport of inorganic phosphate transport in plants. Plant Cell Physiol 36:1–7Google Scholar
- Nautiyal CS (1999) An efficient microbiological growth medium for screening phosphate solubilizing microorganisms. FEMS Microbiol Lett 170:265–270. https://doi.org/10.1111/j.1574-6968.1999.tb13383.x CrossRefPubMedGoogle Scholar
- Ramos C, Molina L, Molbak L, Ramos JL, Molin S (2000) A bioluminescent derivative of Pseudomonas putida KT2440 for deliberate release into the environment. FEMS Microbiol Ecol 34:91–102. https://doi.org/10.1111/j.1574-6941.2000.tb00758.x CrossRefPubMedGoogle Scholar
- Sisaphaithong T, Kondo D, Matsunaga H, Kobae Y, Hata S (2012) Expression of plant genes for arbuscular mycorrhiza-inducible phosphate transporters and fungal vesicle formation in sorghum, barley, and wheat roots. Biosci Biotechnol Biochem 76:2364–2367. https://doi.org/10.1271/bbb.120782 CrossRefPubMedGoogle Scholar
- Tatry MV, Kassis EE, Lambilliotte R, Corratgé C, Aarle IV, Amenc LK, Alary R, Zimmermann S, Sentenac H, Plassard C (2009) Two differentially regulated phosphate transporters from the symbiotic fungus Hebeloma cylindrosporum and phosphorus acquisition by ectomycorrhizal Pinus pinaster. Plant J 57:1092–1102. https://doi.org/10.1111/j.1365-313X.2008.03749.x CrossRefPubMedGoogle Scholar
- Tian H, Yuan X, Duan J, Li W, Zhai B, Gao Y (2017) Influence of nutrient signals and carbon allocation on the expression of phosphate and nitrogen transporter genes in winter wheat (Triticum aestivum L.) roots colonized by arbuscular mycorrhizal fungi. PLoS ONE 12:e0172154. https://doi.org/10.1371/journal.pone.0172154 CrossRefPubMedPubMedCentralGoogle Scholar
- Zhang S, Reddy MS, Kloepper JW (2004) Tobacco growth enhancement and blue mold disease protection by rhizobacteria: relationship between plant growth promotion and systemic disease protection by PGPR strain 90-166. Plant Soil 262:277–288. https://doi.org/10.1023/B:PLSO.0000037048.26437.fa CrossRefGoogle Scholar
- Zhu B, Cao Y, Wang D, Tang X, Hua R, Shi T, Sun L (2013) Survival and chlorpyrifos-degradation of strain Cupriavidus taiwanensis Lux-X1 in different type soils. J Food Agric Envirmon 11:873–876Google Scholar